Large animals, such as bear, elk, moose, buffalo, cattle, wild cats and dogs, can harm humans through predatory attack, defense of territory, young or food, and by offensive actions attributable to numerous other motivations. In the past humans typically protected themselves with a firearm, but such action is now tightly restricted or banned, and in many places is considered unacceptable. People need the ability to quickly and effectively defend themselves by non-lethal means, using methods that are effective, yet do not permanently harm an offending animal in recognition of practical, legal, economic and ethical considerations. An effective, general-purpose deterrent should be easy to carry, quick to access, simple to use, repeatable, yet inexpensive. Such a deterrent would enable humans and other animals to co-exist in habitats that otherwise might become human-occupied only. The remainder of this discussion will refer to bears as the example target animal, because this species generates the greatest need for deterrence. The device, however, will work equally well with any aggressive animal.
Only one generally-accepted, non-lethal class of bear attack deterrent currently exists. These are chemical-based aerosol sprays that generally use a chili pepper derived oleoresin capsicum: brand names include Counter Assault, Frontiersman, Guard Alaska, Mace and UDAP. There are several problems associated with this type of deterrent. The maximum range of an aerosol spray is 25 to 35 feet under ideal conditions. The spray usually is in a narrowly confined stream so that it can reach these distances. Wind can impair properly aiming the spray and it can also shorten the useful range. Wind can also blow the chemical into the user's face, disabling the user instead of the animal. Total operating duration of conventional aerosol sprays is typically 6 to 9 seconds before the container is exhausted. This means that the spray can be used only once. And finally the deterrent does not work on all animals.
Many locations around the world prohibit visitors into wilderness habitats from carrying lethal deterrents or deterrents that can cause permanent injury to an offending animal. Other practical considerations exist for areas that do allow carriage of lethal deterrents, such as firearms. Many people cannot afford or do not know how to use firearms. Misuse of firearms can wound and enrage an animal, transforming it from a potential threat into a deadly one. The potential for accidents with deadly weapons also exist, where those who would protect themselves instead find themselves the victim of their own defense. For these reasons, an economical, simple to use, one-hand operable, non-injurious, all-weather deterrent device with a long operational duty cycle is needed.